HK1242258B - Easily disassembled folding knife - Google Patents

Description

Easy-to-detach folding knife

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 62/481,452, filed April 4, 2017, and U.S. Provisional Application No. 62/340,376, filed May 23, 2016, both of which are incorporated herein by reference in their entirety.

Technical Field

The present invention relates to folding knives, and more particularly, to folding knives that are configured for easy disassembly.

Background Art

There are many available configurations for folding knives. In some of these configurations, the blade of the folding knife can be removed to facilitate cleaning, sharpening, replacement or storage of the blade. For example, U.S. Patents Nos. 7,370,421 and 7,716,839 describe a knife with a detachable blade. Because folding knives with detachable blades are particularly advantageous in harsh conditions (i.e., where the knife may become dirty or dull, and therefore where it is important to be able to clean, sharpen or replace the blade in the field), it is advantageous to provide the folding knife with a detachable blade that is as simple in structure as possible. A simpler configuration can help ensure that the blade remains easy to remove after use in harsh conditions, and ensures that removal of the blade can be completed as quickly and reliably as possible. Therefore, a simple mechanism that allows easy disassembly of the folding knife is desired.

Summary of the Invention

The present invention relates to folding knives that can be disassembled more easily than known folding knives, for example, to clean or replace blades or other components. For example, the folding knives disclosed herein can be disassembled manually, i.e., without the use of additional tools (e.g., without a screwdriver or the like). In some embodiments, the easily disassembled folding knives include a handle portion having a first side portion and a second side portion, the first and second side portions having complementary locking elements that prevent the side portions from separating from each other.

In one exemplary embodiment, a folding knife includes a handle portion, a rotating element, a blade, a locking element, and a cap. The handle portion may include a first side portion and a second side portion laterally spaced from the first side portion. The first side portion may have a first opening, and an outer surface of the first side portion may have a recess surrounding the first opening. The rotating element may extend from an inner surface of the second side portion. The blade may be disposed between the first and second side portions. The blade may have a second opening in a tang portion of the blade. The rotating element may extend through the second opening, enabling the blade to rotate relative to the handle portion about the rotating element between an open position and a closed position. The locking element may be at least partially disposed within the recess of the first side portion. The locking element may be movable between a locked position and an unlocked position. When the locking element is in the locked position, the locking element may prevent disassembly of the first and second side portions, and when the locking element is in the unlocked position, the locking element may allow disassembly of the first and second side portions. The cap may be connected to the first side portion adjacent to the locking element and may cover the first opening. An end portion of the rotating element may be sized to extend through the first opening and into the cap.

In some embodiments, the locking element can include an actuator that can move relative to the cap and the recess of the first side portion between a first position and a second position. When the actuator is in the first position, the locking element can be in the locked position, and when the actuator is in the second position, the locking element can be in the unlocked position.

In some embodiments, the end portion of the rotating element may have a non-circular cross-sectional profile. The locking element may include a first end portion, a second portion having an actuator extending from the first end portion, and a non-circular opening formed in the first end portion. The actuator is movable between a first position and a second position within the recess of the first side portion. Movement of the actuator may cause the non-circular opening to rotate relative to the rotating element such that when the actuator is in the first position, the first end portion of the locking element engages the end portion of the rotating element, and when the actuator is in the second position, the first end portion of the locking element disengages the end portion of the rotating element.

In some embodiments, the end portion of the rotating element can have a hexagonal shape, and the non-circular opening can have a hexagonal shape. When the actuator is in the second position, the hexagonal shape of the end portion of the rotating element and the hexagonal shape of the non-circular opening can be rotationally aligned. When the actuator is in the first position, the hexagonal shape of the end portion of the rotating element and the hexagonal shape of the non-circular opening can be rotationally offset.

In some embodiments, the folding knife may further include: a hole formed in the actuator; a spring disposed in the hole; and a ball disposed at least partially in the hole. An outer surface of the recess may have retaining openings at positions corresponding to the first and second positions of the actuator, such that when the actuator is in the first or second position, the ball is disposed in one of the retaining openings and the spring forces the ball partially into the retaining opening to selectively retain the actuator in the first or second position.

In some embodiments, the cap can include an annular shoulder, a first recessed portion disposed radially inward from the shoulder, and a second recessed portion disposed radially inward from the first recessed portion. The second recessed portion can include a first depth greater than a second depth of the first recessed portion, the locking element can be at least partially disposed in the first recessed portion, the annular shoulder can surround the first end portion except where the annular shoulder includes a groove through which the actuator extends, and the groove can be sized and shaped to allow the actuator to move relative to the groove.

In some embodiments, the inner diameter of the second recessed portion may be larger than the outer diameter of the end portion of the rotating element, such that an annular gap exists separating the end portion of the rotating element from the surrounding wall of the second recessed portion.

In some embodiments, the annular shoulder may include a threaded opening.The folding knife may also include a fastener extending through the first side portion and into the threaded opening to connect the cap to the first side portion.

In some embodiments, the folding knife may further include a spacer disposed between the blade tang and the inner surface of the first side portion. The spacer may have a cylindrical portion disposed in the first opening and a flange portion contacting the blade tang.

In some embodiments, the folding knife may further include a rotatable wheel mounted on an axle between the first and second side portions of the handle portion. The axle may have first and second end portions, the first end portion of the axle may be rotatably mounted to one of the first and second side portions of the handle portion, and the other of the first and second side portions may have a threaded opening that receives the second end portion of the axle. The wheel may be rotatable to move the second end portion into and out of the threaded opening, and the second end portion may have external threads that engage internal threads of the threaded opening to hold the first and second side portions of the handle portion together when the second end portion of the axle is tightened into the threaded opening.

In another exemplary embodiment, a folding knife may include a handle portion, a rotatable wheel, and a blade. The handle portion may include a first side portion and a second side portion laterally spaced from the first side portion. The second side portion may have a threaded opening. The rotatable wheel may be arranged between the first and second side portions and connected to a shaft extending from an inner surface of the first side portion. The shaft may have an externally threaded portion capable of engaging an internal thread of the threaded opening, rotation of the wheel relative to the first side portion in a first direction may cause the externally threaded portion of the shaft to extend into the threaded opening and engage the internal thread, thereby holding the first and second side portions together, and rotation of the wheel in a second direction opposite to the first direction may cause the externally threaded portion to be removed from the threaded opening so that the shaft no longer holds the first and second side portions together. The blade may be rotatably connected to the handle portion such that the blade can rotate relative to the handle portion between an open position and a closed position.

In some embodiments, a portion of the wheel may extend outwardly from the handle portion such that the wheel can be rotated by a user.

In some embodiments, an annular outer surface of the wheel may include circumferentially spaced ridges.

In some embodiments, the folding knife may further include a rotating element extending from an inner surface of the first side portion. The blade may be disposed between the first side portion and the second side portion. The blade may have a first opening in a tang portion of the blade, enabling the blade to rotate relative to the handle portion between the open position and the closed position about the rotating element.

In some embodiments, the second side portion may have a second opening. An outer surface of the second side portion may have a groove surrounding the second opening. The folding knife may also include a locking element that is at least partially disposed within the groove of the second side portion. The locking element is movable between a locked position and an unlocked position. When the locking element is in the locked position, the locking element may prevent disassembly of the first and second side portions, and when the locking element is in the unlocked position, the locking element may allow disassembly of the first and second side portions.

In some embodiments, the folding knife may further include a cap connected to the second side portion adjacent to the locking element and covering the second opening. An end portion of the rotating element may be sized to extend through the second opening into the cap.

In some embodiments, the locking element can include an actuator that can move relative to the cap and the recess of the second side portion between a first position and a second position. When the actuator is in the first position, the locking element can be in the locked position, and when the actuator is in the second position, the locking element can be in the unlocked position.

In some embodiments, the end portion of the rotating element may have a non-circular cross-sectional profile. The locking element may include a first end portion, a second portion having an actuator extending from the first end portion, and a non-circular opening formed in the first end portion. The actuator is capable of moving between a first position and a second position within the recess of the first side portion. Movement of the actuator may cause the non-circular opening to rotate relative to the rotating element such that when the actuator is in the first position, the first end portion of the locking element may engage the end portion of the rotating element, and when the actuator is in the second position, the first end portion of the locking element may disengage the end portion of the rotating element.

In some embodiments, the end portion of the rotating element can have a hexagonal shape, and the non-circular opening can have a hexagonal shape. When the actuator is in the second position, the hexagonal shape of the end portion of the rotating element and the hexagonal shape of the non-circular opening can be rotationally aligned. When the actuator is in the first position, the hexagonal shape of the end portion of the rotating element and the hexagonal shape of the non-circular opening can be rotationally offset.

In another exemplary embodiment, a folding knife may include a handle portion, a rotating element, a blade, a locking element, a cap, and a rotatable wheel. The handle portion may include a first side portion and a second side portion laterally spaced apart from the first side portion. The first side portion may have a first opening, and an outer surface of the first side portion may have a groove surrounding the first opening. The second side portion may have a threaded opening. The rotating element may extend from an inner surface of the second side portion. The blade may be disposed between the first and second side portions. The blade may have a second opening in a tang portion of the blade. The rotating element may extend through the second opening such that the blade can rotate relative to the handle portion about the rotating element between an open position and a closed position. The locking element may be at least partially disposed within the groove of the first side portion. The locking element may be movable between a locked position and an unlocked position. When the locking element is in the locked position, the locking element may prevent disassembly of the first and second side portions, and when the locking element is in the unlocked position, the locking element may allow disassembly of the first and second side portions. The cap may be connected to the first side portion adjacent to the locking element and may cover the first opening. An end portion of the rotating element can be sized to extend through the first opening into the cap. The rotatable wheel can be arranged between the first and second side portions and can be connected to a shaft extending from an inner surface of the second side portion. The shaft can have an externally threaded portion capable of engaging the internal threads of the threaded opening. Rotation of the wheel relative to the first side portion in a first direction can cause the externally threaded portion of the shaft to extend into the threaded opening and engage the internal threads, thereby holding the first and second side portions together, and rotation of the wheel in a second direction opposite to the first direction can remove the externally threaded portion from the threaded opening so that the shaft no longer holds the first and second side portions together.

The various innovations of the present invention can be used in combination or individually. This summary is provided to introduce a selection of concepts further described below in a simplified form. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter. The foregoing and other objects, features, and advantages of the present invention will become more apparent from the following detailed description, which is conducted with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an exemplary folding knife.

2 and 3 are side views of the folding knife of FIG. 1 in an open configuration and a closed configuration, respectively.

4A and 4B illustrate a perspective view and an exploded perspective view, respectively, of another exemplary folding knife.

5 and 6 illustrate side and bottom views, respectively, of a side portion of the folding knife of Figs. 4A and 4B.

7 illustrates a bottom cross-sectional view of a portion of the folding knife of FIGS. 4A and 4B .

FIG. 8 shows the folding knife of FIGs. 4A and 4B in a partially assembled state.

FIG. 9 illustrates an exploded perspective view of another exemplary folding knife.

10 illustrates a bottom cross-sectional view of a portion of the folding knife of FIG. 9 .

11-12 illustrate a folding knife having an exemplary secondary locking mechanism.

13-14 illustrate a folding knife having another exemplary secondary locking mechanism.

FIG. 15A illustrates an exploded perspective view of another exemplary folding knife.

15B-19 illustrate various components of the folding knife of FIG. 15A .

FIG. 20 illustrates another exemplary folding knife.

FIG. 21 shows an exploded perspective view of the folding knife of FIG. 20 .

FIG. 22 shows a partially assembled view of the folding knife of FIG. 20 .

23 illustrates a bottom cross-sectional view of a portion of the folding knife of FIG. 20 .

FIG. 24 illustrates another exemplary folding knife.

FIG. 25 shows a partially assembled view of the folding knife of FIG. 24 .

FIG. 26 shows an exploded perspective view of the folding knife of FIG. 24 .

27-28 each illustrate a partially assembled view of the folding knife of FIG. 24 .

FIG. 29 illustrates another exemplary folding knife in a closed configuration.

FIG. 30 shows the folding knife of FIG. 29 in an open configuration.

31-34 illustrate the various components of the folding knife of FIG. 30 .

FIG. 35 shows an exploded perspective view of the folding knife of FIG. 30 .

FIG. 36 illustrates one embodiment of a side portion of the knife of FIG. 30 .

FIG. 37 illustrates an exploded perspective view of another exemplary folding knife.

FIG. 38 shows the folding knife of FIG. 37 in a closed configuration.

FIG. 39 shows a partial perspective view of the folding knife of FIG. 37 .

40 illustrates a side view of the folding knife of FIG. 37 in a disassembled configuration.

FIG. 41 illustrates a cross-sectional view of a portion of the folding knife of FIG. 37 .

42 illustrates a detailed view of a portion of the folding knife of FIG. 37 in a partially assembled configuration.

DETAILED DESCRIPTION

The present invention relates to folding knives that can be disassembled more easily than known folding knives, for example, to clean or replace blades or other components. For example, the folding knives disclosed herein can be disassembled manually, i.e., without the use of additional tools (e.g., without a screwdriver or the like). In some embodiments, the easily disassembled folding knives include a handle portion having a first side portion and a second side portion, the first and second side portions having complementary locking elements that prevent the side portions from separating from each other.

1-3 , a first embodiment of a folding knife 100 may include a handle portion 102 and a blade 104. The blade 104 may be rotatably/pivotally connected to the handle portion 102 such that the blade 104 can rotate about an axis 106 between an open position for use (as shown in FIG. 2 ) and a closed position for storage (as shown in FIG. 3 ). The handle portion 102 may include a first side portion 108 and a second side portion 110. The first and second side portions may be spaced apart from each other, thereby defining a blade-receiving slot 112 therebetween for receiving the blade when the blade is rotated to its closed position. As shown in FIG. 2 , the first side portion 108 may include a leaf spring 114 (also known as a "liner lock" or "frame lock") that is biased into engagement with the rear edge of the tang of the blade 104 to retain the blade in the open position, as is known in the art.

Figures 4A and 4B to 8 illustrate one embodiment of a folding knife 200, which includes a handle portion 202 and a blade 204, which is rotatably connected to the handle portion 202 for rotational movement about an axis 206. The handle portion 202 may include a first side portion 208 and a second side portion 210. Figure 4A shows a perspective view of the knife 200. Figure 4B shows an exploded perspective view of the knife 200. Figures 5 and 6 show a side view and a bottom view of the first side portion 208, respectively. As shown in the figures, a protruding main cylindrical protrusion 212 (which serves as a rotating element or rotation pin for the blade) can extend laterally from the inner surface of the first side portion 208. The central longitudinal axis of the main cylindrical protrusion 212 can be aligned with the rotation axis 206. As also shown in Figures 5-6, a protruding secondary cylindrical protrusion 214 can extend laterally from the inner side surface of the main cylindrical protrusion 212. As shown, the diameter of the secondary cylindrical protrusion 214 may be smaller than the diameter of the primary cylindrical protrusion 212 , and the central longitudinal axis of the secondary protrusion 214 may be aligned with the central longitudinal axis of the primary protrusion 212 and the rotational axis 206 .

5-6 , a hexagonal locking portion or locking element 216 can be attached to the inner surface of the secondary projection 214. As shown, the width W of the locking portion 216 can be greater than the diameter of the secondary projection 214 so that a locking groove 218 is defined between the main projection 212 and the locking portion 216. The width of the groove 218 (the distance between the rotation pin 212 and the locking element 216) is sized to accommodate the second side portion 210, as described further below. As shown in FIG5-6 , each of the first side portion 208, the main projection 212, the secondary projection 214, and the locking portion 216 has a thickness along the rotation axis that is approximately the same. However, in alternative embodiments, the precise thickness of each of these components along the rotation axis can be any suitable length and is independent of each other.

As best shown in FIG4B , the second side portion 210 can include a hexagonal opening 220 extending through the entire second side portion 210. Advantageously, the hexagonal opening 220 can be sized so that it is only slightly larger than the hexagonal locking portion 216 of the first side portion 208. The opening 220 can also be configured so that when the first and second side portions are positioned adjacent to each other in an assembled (in-use) configuration, the hexagonal shape of the opening 220 is rotationally offset from the hexagonal shape of the locking portion 216 about the rotation axis 206. As best shown in FIG4B , the hexagonal shape of the opening 220 can be rotationally offset from the hexagonal shape of the locking portion 216 by approximately 30 degrees (1/12 of a full rotation) so that the corners of the two hexagonal shapes are rotationally offset as far from each other as possible. The blade 204 can have a circular opening 222. The circular opening 222 can be sized so that its diameter is both larger than the width of the locking portion 216 and larger than the diameter of the main protrusion 212.

While the illustrated embodiment includes a hexagonal locking element 216 and a corresponding hexagonal opening 220, the locking element 216 and the corresponding opening 220 can be any of a variety of shapes. Generally, the knife can include a locking element (e.g., locking element 216) having a non-circular cross-sectional shape (taken along a plane perpendicular to the rotational axis 206) that extends through an opening (e.g., opening 220) of the same or similar shape in a side portion of the handle portion. The locking element 216 and the corresponding opening 220 can be any of a variety of shapes, such as, but not limited to, square, triangular, cross-shaped, etc. It should be noted that in any of the embodiments disclosed herein, regardless of the non-circular cross-sectional shape of the first component (which fits into the correspondingly shaped opening of the second component), the shapes of the first component and the opening can be any of a variety of shapes, including, but not limited to, square, hexagonal, triangular, cross-shaped, oval, etc.

In use, the non-circular locking element cooperates with the non-circular opening to prevent the handle portion side portions 208, 210 from lateral separation when the locking element is rotationally offset from the opening. Conversely, rotating the second side portion 210 so that the opening 220 is rotationally aligned with the locking element 216 allows the handle portion side portions 208, 210 to lateral separation. In certain embodiments, the shape of the opening 220 need not completely correspond to the cross-sectional shape of the locking element 216. In particular, the opening 220 in the side portion 210 can have a non-circular shape that is sized and shaped to: (1) allow the locking element 216 to slide through the opening 220 when the side portion 210 is in a first rotational position, in which the opening 220 is rotationally aligned with the locking element 216; and (2) prevent the locking element 216 from sliding through the opening 220 when the side portion 210 is in a second rotational position, in which the opening 220 is rotationally offset from the locking element 216. As used herein, the term "rotationally aligned" means that the opening 220 in the side portion 210 is in a rotational position relative to the locking element 216 about a central axis (e.g., rotational axis 206) extending through the opening and the locking element such that the locking element can be loaded or slid through the opening in a direction along axis 206. The term "rotationally offset" means that the opening 220 in the side portion 210 is in a rotational position relative to the locking element 216 about a central axis 206 extending through the opening and the locking element such that the locking element cannot be loaded or slid through the opening in a direction along axis 206.

The folding knife 200 (as described above, including the first side portion 208, the second side portion 210, and the blade 204) can be assembled by sliding the blade's opening 222 over the locking portion 216, the secondary protrusion 214, and the primary protrusion 212 to position the blade 204 against the first side portion 208. Referring to Figure 8, the folding knife 200 can be further assembled by positioning the second side portion 210 so that it is rotationally offset from the first side portion 208 by approximately 30 degrees about the axis 206 so that the hexagonal shape of the opening 220 and the hexagonal shape of the locking portion 216 are generally aligned; and then sliding the hexagonal opening 220 of the second side portion 210 over the locking portion 216 and the secondary protrusion 214 until the second side portion 210 rests within the locking slot 218 adjacent the blade. In this configuration, the central longitudinal axes of the protrusions 212, 214 and the locking portion 216, as well as the central longitudinal axes of the opening 222 in the blade 204 and the opening 220 in the second side portion 210, are aligned with the axis of rotation 206.

The second side portion 210 can then be rotated from the position shown in FIG8 until it is rotationally aligned with the first side portion 208 and the hexagonal shape of the opening 220 is rotationally offset from the hexagonal shape of the locking portion 216. In this configuration, the corners 224 of the locking portion 216 extend beyond the edge of the opening 220, thereby preventing removal of the second side portion 210 in a lateral direction away from the first side portion 208, thereby also preventing removal of the blade 204 from the remainder of the knife 200. To remove the second side portion 210 from the first side portion 208, the second side portion 210 can be rotated approximately 30 degrees from the first side portion 208 so that the corners of the locking portion 216 no longer capture the second side portion 210, as in the configuration shown in FIG8; the second side portion 210 can then be slid laterally along the axis 206 away from the first side portion 208. The mechanism for preventing rotation of the second side portion 210 relative to the first side portion 208 in the use position is described in detail below.

The first side portion 208 can be integrally formed with the primary cylindrical projection 212, the secondary projection 214, and the locking portion 216, all formed from a single piece of material, or each of these components can be formed separately and subsequently joined during the manufacturing process, such as by welding. Alternatively, the primary projection 212, the secondary projection 214, and the locking portion 216 can be a unitary component that is removably secured to the first side portion, such as using screws or other removable fasteners. The various components of the knife 200 can be formed from a variety of materials, including metals, plastics, and/or composite materials.

9-10 illustrate another embodiment of a folding knife 300 that may include a blade 304 rotatably coupled to a handle portion 302 for rotational movement about an axis 306. The handle portion 302 may include a first side portion 308, a second side portion 310, a washer 312, a rotation and locking element 314, and a locking screw 316. FIG9 illustrates an exploded perspective view of the knife 300.

The first side portion 308 may include a cylindrical recess 318 formed in an inner surface of the first side portion 308 and having a central longitudinal axis aligned with the rotational axis 306. A circular opening 320, also having a central longitudinal axis aligned with the rotational axis 306, may extend from an end of the recess 318 to an outer surface of the first side portion 308. The shim 312 may be configured to be positioned within the recess 318. The shim 312 may be secured within the recess 318, such as with an adhesive or a press-fit arrangement, to prevent the shim from falling out when the knife is disassembled.

The rotation and locking element 314 can include a first cylindrical portion 322 connected to a second cylindrical portion 324, which itself is connected to a hexagonal locking portion 326. The cylindrical portion 322 serves as a rotation pin or rotation element for the blade. The first cylindrical portion 322 can have a threaded groove 334 at one end (which is configured to receive a locking screw 316) and can have a diameter greater than the diameter of the second cylindrical portion 324. The hexagonal portion 326 can have a width that is also greater than the diameter of the second cylindrical portion 324. Thus, a locking slot 328 can be defined between the first cylindrical portion 322 and the hexagonal portion 326 for receiving the second side portion 310. The screw 316 can be configured to engage the threaded groove of the first cylindrical portion 322 and can have a head with a diameter greater than the diameter of the opening 320.

Assembly 336 may include first side portion 308, washer 312, rotation and locking element 314, and locking screw 316. Assembly 336 may have a structure similar to that of first side portion 208 of knife 200. Blade 304 may have a cylindrical opening 338 having a diameter greater than the diameters of first and second cylindrical portions 322, 324, and greater than the width of hexagonal portion 326.

The second side portion 310 may include a hexagonal recess 330 that communicates with a cylindrical cavity 332 completely contained within the second side portion 310. Advantageously, the hexagonal recess 330 can be sized so that it is slightly larger than the hexagonal portion 326 of the assembly 336. When the assembly 336 and the second side portion 310 are adjacent to each other in the assembled (in-use) position, the hexagonal portion 326 is located within the cavity 332, and the hexagonal shape of the recess 330 is rotationally offset from the hexagonal shape of the portion 326 about the rotation axis 306. The hexagonal shape of the recess 330 can be rotationally offset from the hexagonal shape of the portion 326 by approximately 30 degrees (1/12 of a full rotation) so that the corners of the two hexagonal shapes are rotationally offset as far from each other as possible. The cylindrical cavity 332 can be large enough to allow the hexagonal portion 326 to be located therein and to rotate freely therein.

The folding knife 300 (including the assembly 336, the second side portion 310, and the blade 304, as described above) can be assembled by sliding the opening 338 of the blade 304 over the hexagonal portion 326, the second cylindrical portion 324, and the first cylindrical portion 322, so that the blade 304 abuts the first side portion 308. The folding knife 300 can be further assembled by positioning the second side portion 310 so that it is rotationally offset from the first side portion 308 by approximately 30 degrees about the axis 306, so that the hexagonal shape of the recess 330 and the hexagonal shape of the portion 326 are generally aligned; and then sliding the recess 330 of the second side portion 310 over the hexagonal portion 326 and the second cylindrical portion 324, so that the hexagonal portion 326 is located within the cylindrical cavity 332. In this configuration, the central longitudinal axes of the washer 312 , locking element 314 , locking screw 316 , recess 330 , cavity 332 , and opening 338 may all be generally aligned with the rotational axis 306 .

The second side portion 310 can then be rotated until it is rotationally aligned with the first side portion 308 and the hexagonal shape of the groove 330 is rotationally offset from the hexagonal shape of the portion 326. In this configuration, the corners of the hexagonal portion 326 extend beyond the edge of the groove 330, thereby preventing lateral removal of the second side portion 310 away from the assembly 336 (including the first side portion 308), thereby also preventing removal of the blade 304 from the knife 300. To remove the second side portion 310 from the assembly 336, the second side portion 310 can be rotated approximately 30 degrees relative to the assembly 336 so that the corners of the hexagonal portion 326 no longer capture the second side portion 310, and the second side portion 310 can then be slid away from the assembly 336. Each component of the knife 300 can be formed from a variety of materials, including metal, plastic, and/or composite materials.

To further secure the two halves of the knife's handle portion to each other, a secondary securing mechanism can be provided. This secondary securing mechanism can help ensure that the two halves do not inadvertently rotate relative to each other and thereby become loose. A variety of such mechanisms can be used, and one embodiment is shown in Figures 11-12. As shown in Figures 11-12, the knife 400 can include a removable first side portion 402 having a distal portion 404 and a proximal portion 406; and a second side portion 408. The distal portion 404 can include a notch 410, and the proximal portion 406 can include one or more grooves 412 that accommodate a spring 418, and a protrusion 414 configured to fit within the notch 410. The second side portion 408 can include one or more protrusions or bumps 416 configured to extend into their respective grooves 412. The spring 418 can be retained within the groove 412 by various suitable means, such as a housing (not shown) positioned over the groove 412.

The spring 418 is configured to apply a biasing force that urges the proximal portion 406 in the direction of arrow 420 toward the distal portion 404, causing the protrusion 414 to engage the notch 410, thereby preventing the distal portion 404 from rotating relative to the remainder of the handle portion. The distal portion 404 can be disassembled by sliding the proximal portion 406 rearwardly in the direction of arrow 422 against the biasing force of the spring until the protrusion 414 is clear of the notch 410. The distal portion 404 can then be rotated relative to the hexagonal locking element and can be slid laterally away from the second side portion 408, as described in detail above.

Another exemplary embodiment of a secondary securing mechanism that can be used with a knife is shown in Figures 13-14. Figure 13 shows a knife 500, which includes a distal portion 502 and a proximal portion 504 of a first side portion of the knife 500; Figure 14 shows a cross-sectional view of the knife 500 taken along line 14-14 of Figure 13. The secondary locking portion shown in Figures 13-14 is similar to the secondary locking portion shown in Figures 11-12, except that it uses a dovetail locking system, rather than notches and protrusions, to rotationally lock the distal portion 502, thereby preventing the knife from becoming loose. For example, the distal portion 502 can include one or more dovetail-shaped protrusions 506 that are shaped to mate with one or more dovetail-shaped grooves 508 of the proximal portion 504.

In another embodiment, a removable spring clip can be used to prevent the side portions of the handle portion from rotating relative to each other. In one embodiment, a clip includes two opposing spring legs that can be slid onto the first and second side portions 208, 210, thereby providing a clamping force against the side portions, thereby holding them together.

FIG15A and FIG15B through FIG19 illustrate an alternative embodiment of an easily removable folding knife 600. The knife 600 may include a handle portion 602 and a blade 604. The handle portion 602 may include a first side portion 606, a second side portion 608, a liner lock portion 610, and a locking portion 612. Referring to FIG15A , the first side portion 606 may include three engaging elements 614A-C, each having a respective recess 616, which may have a flat oval shape (e.g., an oval shape with flat edges). Each engaging element 614 may also include a respective generally circular opening 618 extending through the first side portion 606 and a respective flat oval opening 620, the respective circular opening 618 extending through the first side portion 606, the respective flat oval opening 620 extending away from the respective circular opening 618 and extending through the first side portion 606.

The groove 616 can be formed in a front surface 622 of the first side portion 606, which can be the exposed surface of the first side portion 606 when the knife 600 is fully assembled. Additionally, the flat oval opening 620 can have a width W1 that is less than a width W2 of the groove 616 (see FIG. 19 ), which can be approximately equal to the diameter of the circular opening 618, so that a lip or ledge 626 is formed in the first side portion 606. In some embodiments, the groove 616 can be formed by removing material from the first side portion 606, for example, by removing between about 1/4 and about 3/4 of the thickness of the first side portion 606, or by removing about 1/2 of the thickness of the first side portion 606. In the illustrated embodiment, the knife 600 includes three engagement elements 614A-C, but in alternative embodiments, fewer or additional engagement elements can be used.

As shown, two of the engagement elements 614A and 614B can be located near the distal portion of the handle portion 602 (and thus can be referred to as distal engagement elements), and a third engagement element 614C can be located near the proximal portion of the handle portion 602 (and thus can be referred to as a proximal engagement element). Additionally, the flattened oval shapes of the respective components of the distal engagement elements 614A and 614B can be generally aligned with the length of the first side portion 606. That is, the flat edges of the flattened oval openings 620 and recesses 616 of the distal engagement elements 614A, 614B can be parallel or substantially parallel to the length of the first side portion 606, the top surface 628 of the first side portion 606, and/or the bottom surface 630 of the first side portion 606.

The flattened oval shape of the respective components of the proximal engagement element 614C can be angularly offset from the length of the first side portion 606. That is, the flattened oval opening 620 and the flat sides of the recess 616 of the proximal engagement element 614C can be angularly offset from the top surface 628, the bottom surface 630, and/or the length of the first side portion 606, and thus, from the respective flat sides of the components of the distal engagement elements 614A, 614B. The flat sides of the opening 620 of the proximal engagement element can be offset from the flat sides of the opening 620 of the distal engagement element by an angle α, which can be, for example, between approximately 5 degrees and approximately 45 degrees.

The rear surface 624 ( FIG. 15B ) of the first side portion 606—which can be an unexposed or inner surface of the first side portion 606 when the knife 600 is fully assembled—can include a pin 632 ( FIG. 15A ) and a support pad 634 ( FIG. 15B ). When the knife 600 is in the fully assembled configuration, the pin 632 can engage the locking portion 612, as described further below. The support pad 634 can protrude outward from the rear surface 624 to reduce the surface area of contact between the first side portion 606 and the blade 604 when the knife is in the fully assembled configuration, as explained further below. The support pad 634 can also be made of a different material than the rest of the first side portion 606, such as a relatively lubricious metal material, to reduce friction between the blade 604 and the first side portion 606. The support pad 634 can have an overall semicircular shape that surrounds the flat, oval opening 620 of the engagement element 614A and partially surrounds the circular opening 618 of the engagement element 614A. In some embodiments, a spacer may be used in place of the support pad 634 .

The second side portion 608 can have a profile that generally matches the profile of the first side portion 606. As best shown in FIG15A, the second side portion 608 can include three engagement elements 636A-C that protrude outwardly from an inner surface 638 of the second side portion 608, which can be the unexposed surface of the second side portion 608 when the knife 600 is fully assembled. The second side portion 608 can include more or fewer than three engagement elements 636, but in many embodiments, the second side portion 608 can have the same number of engagement elements 636 as the first side portion 606 has engagement elements 614. The engagement elements 636 of the second side portion 608 can be configured to engage the engagement elements 614 of the first side portion 606, as described further below. The positions of the engagement elements 636 on the second side portion 608 can also be configured so that the engagement elements 636 can be aligned with their respective circular openings 618 simultaneously.

Each engagement element 636A-C can include a relatively wide base portion 640, a relatively narrow neck portion 642, and a relatively wide head portion 644. In the illustrated embodiment, the neck portion 642 and the head portion 644 can include respective screw portions that can be threaded through the respective base portions 640 and into the threaded opening 676 of the body 646 of the second side portion 608. As shown, the engagement element 636A can include a spacer 648 disposed between the body 646 of the second side portion 608 and the base portion 640 of the engagement element 636A. When the knife 600 is in a fully assembled configuration, the spacer 648 can reduce the surface area of contact between the second side portion 608 and the blade 604, as explained further below. The spacer 648 can also be made of a different material than the rest of the second side portion 608, such as a relatively lubricious metal material, to reduce friction between the blade 604 and the second side portion 608. In some embodiments, the spacer need not be a component of the engagement element 636A and can be a separate component.

As shown, the second side portion 608 can also include a pin 650 that protrudes outwardly from the inner surface 638 of the second side portion 608. The pin 650 can engage the locking portion 612 when the knife 600 is in the fully assembled configuration, as described further below.

The liner lock portion 610 can have a general shape that generally matches the contours of the first and second side portions 606, 608 and can include a relatively thin piece of material so that the proximal and distal leaf springs 652, 654 can be relatively easily manipulated by a user. The liner lock portion 610 can include four openings 656A-D that can be sized and positioned so that the liner lock portion 610 can be positioned adjacent to the second side portion 608, with the engagement elements 636A-C extending through the openings 656A-C, respectively, and the pin 650 extending through the opening 656D. When the knife 600 is in a fully assembled configuration, the distal leaf spring 654 can prevent the blade 604 from being inadvertently closed after the user has opened the blade 604, and the proximal leaf spring 652 can prevent the locking portion 612 from accidentally moving to an unlocked position, as further described below.

The locking portion 612 can include a rotation opening 658 that can be sized to fit on the bottom portion 640 of the engagement element 636C so that the locking portion 612 can be rotated about the engagement element 636C, for example, from a locked position (when the knife is fully assembled) to an unlocked position that allows assembly or disassembly of the knife. The locking portion 612 can also include a notch 660 that can be positioned to fit over the pin 650 when the rotation opening 658 is installed on the engagement element 636C. The shape of the notch 660 can allow the pin 650 to move through the notch 660 when the locking portion 612 is rotated about the engagement element 636C. For example, the notch 660 can include a first end 660A and a second end 660B such that the pin 650 is located at the first end 660A when the knife 600 is in a fully assembled configuration (and the locking portion 612 is in a locked position, as shown in phantom in FIG17 ), and such that the pin 650 is located at the second end 660B when the locking portion 612 is in an unlocked position, thereby allowing the knife to be assembled or disassembled (as shown in solid lines in FIG17 ). The locking portion 612 can also include an opening 662 that can be positioned to receive the pin 632 of the first side portion, as further described below.

The locking portion 612 can further include a locking surface 664 that can be positioned to engage the proximal portion of the proximal leaf spring 652 when the locking portion 612 is in the locked position. The locking portion 612 can also include a manipulation portion 666 extending outwardly from the rear end of the handle portion that can allow a user to more easily manipulate the locking portion 612 with their fingers.

The blade 604 can include a rotation opening 668 that is sized to be mounted on the bottom portion 640 of the engagement element 636A, rather than being mounted on the spacer 648. In this way, the engagement element 636A acts as a rotation pin or rotation element for the blade. The blade can also include a first locking surface 670 and a second locking surface 672, the first locking surface 670 being positioned to engage the distal portion of the distal leaf spring 654 when the blade 604 is in the open position, and the second locking surface 672 being positioned to engage the bottom portion 640 of the engagement element 636B when the blade is in the open position. In this way, the distal leaf spring 654 and the engagement element 636B can be used to prevent the blade 604 from moving relative to the handle portion 602 when the blade is in the open position. Additionally, the blade can be configured such that the first locking surface 670 is positioned to engage the bottom portion 640 of the engagement element 636B when the blade 604 is in the closed position, such that the blade 604 cannot be rotated about the engagement element 636A to the extent that the blade is exposed exteriorly of the handle portion 602, such as by rotating beyond the top surface 628. The blade 604 can also include an extension 674 that can extend exteriorly of the handle portion 602 when the blade 604 is in the closed position, which can allow a user to more easily manipulate and open the blade 604 using their fingers.

With the various components described in this manner, the assembly and disassembly of the knife 600 will now be explained. To assemble the knife 600, the second side portion 608 (including the engagement element 636) can be placed on a flat surface, with the engagement element 636 protruding outward from the flat surface. The liner lock portion 610 can then be placed on the second side portion, with the engagement elements 636 extending through the respective openings in the liner lock portion 610. The locking portion 612 can then be placed on the liner lock portion 610, with the pin 650 positioned at the second end 660B of the notch 660 (i.e., in the unlocked position shown in FIG. 16 ). The blade 604 can then be placed on the liner lock portion, such that the engagement element 636A extends through the rotational opening 668. The first side portion 606 can then be placed on the blade 604 and the locking element 612, such that the head portions 644 of the engagement elements 636 extend through the respective circular openings 618 of the engagement element 614. Thus, the head portion 644 may be positioned within each groove 616 , and the neck portion 642 may be positioned within each circular opening 618 .

The locking portion 612 can then be rotated about the engagement portion 636C from the open (unlocked) position to the closed (locked) position, as indicated by arrow 680 in FIG. 19 . As the locking portion 612 is rotated in this manner, the engagement of the opening 662 of the locking portion 612 with the pin 632 of the first side portion 606 causes the first side portion 606 to rotate slightly about the element 636A and translate distally, as indicated by arrow 682, until the first side portion 606 is aligned with the second side portion. In this position, the head portion 644 is located within the respective recess 616, and the neck portion 642 is located within the respective flat oval opening 620. Thus, the first side portion 606 is restricted from separating from the second side portion 608 because the head portion 644 engages the respective lip 626. When the locking portion 612 reaches the closed position, the proximal leaf spring 652 engages the locking surface 664, thereby restricting movement of the locking portion toward the open position; and the knife 600 is in the fully assembled configuration, as shown in FIG. 18 . The blade 604 can then be rotated to an open position, where it is locked in the open state by the distal leaf spring 654. The user can manually depress the distal leaf spring 654 to close the blade 604. Each lip 626 can be an inclined surface of increasing thickness that extends from the opening 618 to the end of the groove 616 opposite the opening 618. In this manner, as the head portion 644 slides against the inclined lip 626, the frictional contact between the head portion 644 and the lip 626 increases, and the spacing between the side portions 606, 608 decreases to tightly hold the side portions 606, 608, the blade 604, and the liner 610 in their assembled state.

To disassemble the knife 600, the user can manually depress the proximal leaf spring 652 and rotate the locking portion 612 toward the unlocked state, thereby causing the first side portion 606 to rotate and translate proximally until the neck portion 642 of the engagement element 636 is located within the circular opening 616, at which position the various components can then be laterally disassembled from each other.

20-23 illustrate an alternative embodiment of an easily disassembled folding knife 700. The knife 700 may include a handle portion 702 and a blade 704. The handle portion 702 may include a first side portion 706, a second side portion 708, and a locking button 744. The first side portion 706 may include a body 710, a circular recess 712 formed in an outer surface 714 of the body 710 (i.e., the exposed surface when the knife 700 is fully assembled), and a flat oval opening 716 extending from the recess 712 through the body 710 to form a lip or lug 717. The first side portion 706 may also include a protruding pin 718 extending from an inner surface 720 ( FIG. 23 ) of the body 710. The recess 712, opening 716, and pin 718 may be located at a distal portion of the first side portion 706. The proximal portion of the handle portion (first side portion) 706 may include a locking portion 722 that is biased from the body 710 in the direction of the inner surface 720, such as by an intermediate biasing element 723. The locking portion 722 may include a circular locking groove 724.

The second side portion 708 can include a body 726, with the engagement element 728 including a relatively wide base portion 730, a relatively narrow neck portion 732, and a relatively wide head portion 734 having a flat oval shape that matches (but is slightly smaller than) the flat oval shape of the flat oval opening 716 of the first side portion 706. The second side portion 708 can also include a semicircular groove 736 that is partially positioned around the engagement element 728. The second side portion 708 can also include a locking portion 738 that is offset from the body 726 in the direction of the inner surface 740 ( FIG. 23 ) of the body 726, such as by an intermediate biasing element 741. The locking portion 738 can include a circular locking opening 742.

The blade 704 can include a circular opening 746 sized to fit over the engagement element 728, a first locking surface 748 positioned to engage the pin 718 when the knife 700 is in the fully assembled configuration and the blade 704 is in the closed position, and a second locking surface 750 positioned to engage the pin 718 when the knife 700 is in the fully assembled configuration and the blade 704 is in the open position. The blade 704 can also have a shape that includes an extension 752 that extends from the fully assembled knife 700 when the blade is in the open and closed positions to assist the user in opening and/or closing the blade. The locking button 744 can include a relatively wide base 754, a relatively narrow head 756, and a spring 758 disposed in the recess 724 and extending away from the base 754 in a direction away from the head 756.

As shown in Figure 21, the knife 700 may also include a sharpening element 760, which is connected to the inner surface 740 of the second side portion 708, for example. For example, the sharpening element may include a sharpening steel element, or a diamond sharpening element, or any suitable abrasive surface that allows the user to sharpen a blade (e.g., blade 704) thereon. Any knife described herein may include such a sharpening element, for example, to facilitate sharpening the blade in the field. Advantageously, this avoids the need to carry a separate sharpener for sharpening the blade of the knife. If the blade 704 needs to be sharpened, the knife can be easily disassembled, preferably without the use of any tools; the blade can be sharpened on the sharpening surface 760 of the handle portion 708. In other embodiments, the element 760 may be a detachable sharpening element that can be removed from the handle portion 708 for use.

To assemble the knife 700, the opening 746 of the blade can be positioned over the engagement element 728 of the second side portion 708. The flat oval opening 716 of the first side portion 706 can then be aligned with the flat oval head portion 734 of the second side portion 708, and the first side portion can be placed on the second side portion so that the head portion 734 is located within the recess 712, the neck portion 732 is located within the opening 716, and the pin 718 is located within the groove 736, as shown in FIG22. The button 744 can then be positioned so that the spring 758 is installed within the circular recess 724. The first side portion 706 can be locked to the second side portion 708 by depressing the button into the recess 724 (e.g., by manually pressing the button 744 to compress the spring 758) and rotating the first side portion 706 so that the locking portion 722 moves toward the locking portion 738 (and the pin 718 moves within the groove 736), as indicated by arrow 762 in FIG22. That is, the first side portion 706 is restricted from moving away from the second side portion by the engagement of the head portion 734 with the lip edge 717 and the engagement of the locking portion 738 with the locking portion 722.

Additionally, by rotating the first side portion until the button 744 aligns with the circular locking opening 742, the button can be urged into engagement with the opening 742 by a spring 758, such that the head 756 is positioned within the opening 742 and the base 754 is positioned within the recess 724, as shown in FIG23 , thereby preventing any further relative rotation between the side portions 706, 708. To disassemble the knife 700, the button can then be depressed (e.g., manually) until its head 756 is no longer positioned within the opening 742. The first side portion 706 can then be rotated to separate the locking portions 722, 738 and align the head portion 734 with the opening 716. The components can then be laterally disassembled from one another. In some embodiments, the knife 700 includes a washer or similar component, as described above, for example, with respect to the knife 600. In some embodiments, the knife 700 includes a liner lock or other similar component, as described above, for example, with respect to the knife 600. In one embodiment, the base 754 of the button 744 can be configured to be retained within the recess 724 when the first side portion 706 is separated from the second side portion 708.

Figures 24-28 illustrate an alternative embodiment of a folding knife 800 that can be easily disassembled. The knife 800 can include a handle portion 802 and a blade 804. The handle portion 802 can include a first side portion 806 and a second side portion 808. The first side portion 806 can include a body 810, two circular recesses 812, 814 formed in the outer surface of the body 810 (i.e., the exposed surface when the knife 800 is fully assembled), and two respective flat oval openings 818, 820 extending from the recesses 812, 814 through the body 810 to form respective lips or lugs 822, 824. The first side portion 806 can also include a protruding pin 826 extending from the inner surface of the body 810. The groove 812 , the opening 818 , and the pin 826 may be located at a distal portion of the first side portion 806 , while the groove 814 and the opening 820 may be located at a proximal portion of the first side portion 806 .

The second side portion 808 can include a body 830, an engagement element 832 including a relatively wide base portion 834, a relatively narrow neck portion 836, and a relatively wide head portion 838 having a flat oval shape that matches (but is slightly smaller than) the flat oval shape of the flat oval opening 818 of the first side portion 806. The second side portion 808 can also include a divot 864 that can receive one end of the pin 826 when the knife 800 is fully assembled. The second side portion 808 can also include a locking portion 840 that includes an actuating arm 842 and a securing element 843 mounted to the arm 842. The securing element 843 includes a relatively narrow neck portion 844 and a relatively wide head portion 846 having a flat oval shape that matches (but is slightly smaller than) the flat oval shape of the flat oval opening 820 of the first side portion 806. The actuator arm 842 and the fixing element 843 can be connected to each other so that rotation of the arm 842 causes rotation of the fixing element 843. The second side portion 808 can also include a pair of pins 848 that can prevent the actuator arm 842 from rotating too far into the handle portion 802 when the knife 800 is fully assembled.

As shown, the flat oval openings 818, 820 of the first side portion 806 can be oriented in the same direction. That is, the flat sides of the flat oval openings 818, 820 can be generally parallel to each other. Also as shown, the flat oval head portion 838 can be oriented so that the flat sides of the head portion 838 are angularly offset from the flat sides of the opening 818 when the knife 800 is fully assembled, as shown in Figure 24. In addition, the head portion 846 of the fixing element 843 can be oriented so that the flat sides of the head portion 846 are angularly offset from the flat sides of the opening 820 when the knife 800 is fully assembled (as shown, they are offset by approximately 90 degrees when the knife 800 is fully assembled, but various angular offsets are suitable).

The first and second side portions 806, 808 of the knife 800 can include notches 858, and the actuator arm 842 can include a gripping element 860 (e.g., a fingernail indentation) aligned with the notch 858 to further facilitate manual operation (e.g., rotation) of the actuator arm 842. The blade 804 can include a circular opening 850 sized to fit over the engagement element 832, a first locking surface 852 positioned to engage the pin 826 when the knife 800 is in a fully assembled configuration and the blade 804 is in a closed position, and a second locking surface 854 positioned to engage the pin 826 when the knife 800 is in a fully assembled configuration and the blade 804 is in an open position. The blade 804 can also have a shape that includes an extension 856 that extends from the fully assembled knife 800 when the blade is in the open and closed positions to assist the user in opening and/or closing the blade.

To assemble the knife 800, the opening 850 of the blade can be positioned over the engagement element 832 of the second side portion 808, as shown in FIG28. The flat oval opening 818 of the first side portion 806 can then be aligned with the flat oval head portion 838 of the second side portion 808, and the first side portion 806 can be placed on the second side portion such that the head portion 838 is located within the recess 812 and the neck portion 836 is located within the opening 818, as shown in FIG27. The locking portion 840 can then be rotated such that the opening 820 is aligned with the head portion 846 when the first side portion 806 is rotated to bring the opening 820 to the head portion 846. The first side portion 806 can then be rotated about the engagement element 832 such that the opening 820 moves toward the locking portion 840 and the head portion 846. Once the first side portion 806 has been rotated so that the opening 820 overlaps the head portion 846, the opening 820 can be seated on the locking portion 840 so that the neck 844 is located within the opening 820 and the head 846 is located within the groove 814, as shown in Figure 25. The locking portion 840 can then be rotated so that the head 846 is no longer aligned with the opening 820, such as by manually operating (e.g., rotating) the actuator arm 842 to the closed or locked position shown in Figure 24. Thus, the first side portion 806 can be restricted from moving away from the second side portion 808 by the engagement of the head portion 838 with the lip 822 and the engagement of the head 846 with the lip 824.

To disassemble the knife 800, the locking portion 840 can be rotated to an open or unlocked position to align the head 846 with the opening 820. The first side portion 806 can then be lifted off the locking portion 840 and rotated to align the opening 818 with the head portion 838. The components of the knife 800 can then be laterally disassembled from one another. In some embodiments, the knife 800 includes a washer 862 or similar component, as described above, for example, with respect to the knife 600. In some embodiments, the knife 800 includes a liner lock or other similar component, as described above, for example, with respect to the knife 600. Additionally, one or both of the lips 822, 824 can include an inclined surface with increasing thickness that contacts the respective head portion 838, 846. As the side portion 806 rotates from the position shown in FIG. 27 to the position shown in FIG. 24, the frictional contact between the inclined surface and the respective head portion increases, and the lateral spacing between the side portions 806, 808 decreases, thereby firmly holding the side portions 806, 808 and the blade 804 in the assembled state.

Figures 29-36 illustrate an alternative embodiment of a folding knife 900 that can be easily disassembled. The knife 900 can include a handle portion 902 and a blade 904. The handle portion 902 can include a first side portion 906 and a second side portion 908. The first side portion 906 can include a body 910 and two recesses 912, 914 formed in an outer surface 916 of the body 910 (i.e., an exposed surface when the knife 900 is fully assembled). As best shown in Figure 35, each recess 912, 914 can have a keyhole-like shape or include a circular portion 918 with a scalloped portion 920 extending away from the circular portion 918. The first side portion 906 can further include two circular openings 922, 924 extending through the body 910 from the center of each circular portion 918.

The first side portion 906 may also include two rotatable locking or securing elements or locks 926, 928 positioned within respective recesses 912, 914. The locks 926, 928 may have a shape comprising a circle with a circular recess 927, 929 at its center and a hexagonal opening 930, 932 at its center. The locks may also have respective actuators or levers 934, 936 extending away from the circular portion. The actuators 934, 936 may be positioned within the respective sector 920 of the recess 912, 914 so that a user can move the actuators from one side of the sector 920 to the other side of the sector 920 to rotate the hexagonal openings 930, 932. The first side portion 906 may also include several screws 938 that are threaded into the body 910 such that the heads of the screws overlap the grooves 912 , 914 and the locks 926 , 928 to retain the locks 926 , 928 within the grooves 912 , 914 .

The second side portion 908 can include a body 940, a spacer 942, a distal engagement portion 944, a proximal engagement portion 946, and a pin 948. The distal engagement portion 944 can include a relatively wide base portion 950, a relatively narrow neck portion 952, and a relatively wide head 954. Similarly, the proximal engagement portion 946 can include a relatively wide base portion 956, a relatively narrow neck 958, and a relatively wide head 960. The heads 954, 960 can have a shape that matches but is slightly smaller than the shape of the hexagonal openings 930, 932. In some embodiments, the rotatable locks 926, 928 can be made of the same material as the heads 954, 960 (e.g., steel) so that the heads 954, 960 can easily slide through the hexagonal openings 930, 932 in the locks 926, 928.

The spacer 942 can be attached to the body 940, for example, by an adhesive, by screws 962 (as shown), or by various other suitable means. The distal engagement portion 944 can be positioned within a recess 943 in the body 940 and attached to the body 940 by screws 945 or by various other suitable means. The proximal engagement portion 946 can be positioned within a recess 947 in the spacer 942 and attached to the spacer 942 by screws 949 or by various other suitable means. A pin 948 can be positioned to engage a blade (described below) to prevent the blade from rotating further than desired.

The blade 904 can include a circular opening 964 sized to fit over the distal engagement portion 944 and a semicircular groove 966 positioned relative to the opening 964 to fit over the pin 948 when the opening 964 is mounted over the engagement portion 944. The blade 904 can also include an extension 968 that can extend independently of the handle portion 902 when the knife 900 is fully assembled and the blade is in the open or closed position to assist a user in opening and/or closing the blade 904.

As shown in Figure 35, the knife 900 can also include a recessed compartment 974, which is contained in the second side portion 908. The compartment 974 can allow the user of the knife 900 to store various items in the first side portion 906 of the knife 900, such as other blades or tools, flint and steel, blade sharpeners, matches, medicine, or other small enough items that the user may want to obtain in the field. Any knife described herein can include this type of internal compartment, for example, for the convenience of storing and hiding small items in the field. The recessed compartment 974 can be covered by a lid 976, which can be rotatably connected to the inner surface of the second side portion 908.

To assemble the knife 900, the opening 964 of the blade 904 can be positioned on the engagement element 944 so that the pin 948 is located within the groove 966. The locks 926, 928 can then be actuated so that the hexagonal openings 930, 932 are generally aligned with the heads 954, 960. The first side portion 906 can then be placed on the second side portion 908 so that the engagement portions 944, 946 extend through the openings 922, 924, 930, 932 so that the necks 952, 958 are located within the hexagonal openings 930, 932 and the heads 954, 960 are located within the circular grooves 927, 929. The locks 926, 928 can then be actuated (rotated) so that the hexagonal openings 930, 932 are no longer aligned with the heads 954, 960, thereby locking the first side portion 906 to the second side portion 908 in a manner similar to that described above. In some embodiments, the head portions 954, 960 may include an angled surface having a variable thickness that contacts the respective locks 926, 928, and the surface of the locks 926, 928 that contacts the head portions 954, 960 may include a complementary angled surface having a variable thickness. Thus, as the locks 926, 928 rotate from the unlocked position to the locked position, the frictional contact between the head portions 954, 960 and the locks 926, 928 increases and the lateral spacing between the side portions 906, 908 decreases, thereby firmly holding the side portions and the blade together in an assembled state.

To disassemble the knife 900, the locks 926, 928 can be actuated to align the hexagonal openings 930, 932 with the heads 954, 960, and then the components of the knife 900 can be disassembled laterally relative to each other. In some embodiments, the knife 900 includes a spacer 970 or similar component, as described above, for example, with respect to the knife 600. In some embodiments, the knife 900 includes a liner lock or other similar component, as described above, for example, with respect to the knife 600.

FIG36 illustrates one embodiment of a second side portion 908, which includes a recess 978 formed therein and a secondary tool element 980 rotatably connected to the second side portion 908 via a rotational element 982. In a particular embodiment, the recess 978 may be formed on the inner surface of the side portion 908, although in other embodiments, it may be formed on the outer surface of the side portion 908. In this embodiment of the second side portion 908, the secondary tool 980 can be rotated relative to the second side portion from a closed position, in which the tool 980 is located within the recess 978, to an open position, in which the tool 980 is accessible. Thus, the secondary tool 980 can be concealed within the knife 900 when the user is using the blade 904 of the knife 900 or when the user is not using the knife 900. When the user desires to use the secondary tool 980, the tool 980 can be rotated about the element 982 to the open position for use. If desired, the side portion 908 can be detached from the knife, and the side portion 908 and tool element 980 can be used as separate tools. In various embodiments, tool 980 may include a blade, a screwdriver, a can opener, a sharpener for sharpening blade 904, a nail file, or any other suitable tool known in the art.

37-42 illustrate an alternative embodiment of a folding knife 1000. As shown in FIG37, the knife 1000 may include a handle portion 1002 and a blade 1004, and may be constructed similarly to the knife 900 shown in FIG29-36. The handle portion 1002 may include a first side portion 1006 and a second side portion 1008.

37 , 38 and 40 , the first side portion 1006 of the handle portion 1002 may include a body 1005, a first opening 1007, a first groove 1010 formed in an outer surface 1012 of the body 1005 (i.e., an exposed surface when the knife 1000 is fully assembled) and surrounding the first opening 1007, a second opening 1020 extending through the body 1005, and a second groove 1011 formed in an inner surface 1013 (i.e., a hidden surface when the knife 1000 is fully assembled) and surrounding the second opening 1020.

38 , the first recess 1010 can be configured similarly to the recess 912 of the knife 900 and can accommodate a locking or retaining element 1014. As best shown in FIG41 and FIG42 , the locking element 1014 can include a first end portion 1014a, a second end portion in the form of an actuator or lever 1014b extending from the first end portion and directed toward the outer surface 1012 of the first side portion 1006, and a hexagonal (or other non-circular) opening 1016 ( FIG40 ) formed in the first end portion 1014a and directed toward the inner surface 1013 of the first side portion 1006. The first end portion 1014a of the locking element 1014 can have a circular shape as shown, although in other embodiments it can have various other shapes (e.g., square).

38 , the actuator 1014b can be configured such that a user can apply manual pressure thereto by a user's digit (e.g., a finger or thumb) to move the actuator 1014b within the first groove 1010 from one side of the groove 1010 to the other, causing the hexagonal opening 1016 to rotate relative to the first opening 1007, similar to the manner described above with respect to the locking element 926. The first groove 1010 can also include retaining openings 1036 ( FIG. 41 ) on either side of the first groove 1010, as discussed in further detail below.

40 , in some embodiments, the second opening 1020 of the first side portion 1006 can be configured to receive a threaded insert or nut 1009. The insert 1009 can have internal threads that are configured to engage corresponding external threads of the second side portion 1008, as described further below. In some embodiments, the insert 1009 can be fixedly secured to the first side portion 1006, for example, by a tolerance fit, adhesive, and/or fasteners. In other embodiments, the insert 1009 can be removably connected to the first side portion 1006.

In some embodiments, the second opening 1020 can have a non-circular shape, and the insert 1009 can have an outer surface having a non-circular shape that corresponds to the non-circular shape of the second opening 1020. For example, the outer surfaces of the second opening 1020 and the insert 1009 can have flat surfaces 1025. Configuring the second opening 1020 and the insert 1009 in this manner can prevent relative rotational movement between the second opening 1020 and the insert 1009 (e.g., when assembling and/or disassembling the knife 1000, as described further below).

In lieu of insert 1009, second opening 1020 may comprise an internally threaded bore formed directly in first side portion 1006 and configured to engage corresponding external threads of second side portion 1008 (e.g., threads of shaft 1028, as described below).

Still referring to FIG40 , the second side portion 1008 of the handle portion 1002 can include a body 1021 and a rotational element 1022 extending from an inner surface 1023 of the body 1021 (i.e., a hidden surface when the knife 1000 is fully assembled). In the illustrated embodiment, the rotational element 1022 includes a cylindrical base 1022a, a cylindrical middle portion 1022b having a smaller diameter than the base 1022a, and a non-circular or non-cylindrical end portion 1022c that serves as a locking feature configured to engage and disengage with the locking element 1014, as further described below. The end portion 1022c can have a hexagonal cross-sectional profile (in a plane perpendicular to the axis of rotation defined by the rotational element 1022), as shown, or can have other non-circular shapes. The rotational element 1022 can be sized to extend through the circular opening 1024 in the blade 1004, through the first opening 1007 of the first side portion 1006, and through the hexagonal opening 1016 of the locking element 1014. In the fully assembled state of the knife, the base 1022a is located within the opening 1024 of the blade 1004, and the blade can rotate relative to the base 1022a between the open position and the closed position of the blade. The end portion 1022c can be configured to selectively engage the locking element 1014 (e.g., similar to the manner in which the distal engagement portion 944 engages the locking element 926).

The second side portion 1008 may also include a secondary securing mechanism. The secondary securing mechanism may include a rotatable member in the form of a wheel 1026 connected to a shaft 1028. The wheel 1026 may be fixedly secured to the shaft 1028, and the shaft 1028 may be rotatably connected to the body 1021. In a particular embodiment, the shaft 1028 is rotatable relative to the body 1021 of the second side portion 1008, but desirably (but not necessarily) is not removable from the body 1021 of the second side portion 1008. In some embodiments, the wheel 1026 and the shaft 1028 may be integrally formed from a single, unitary piece of material. In other embodiments, the wheel 1026 and the shaft 1028 may be formed from separate pieces that are fixedly fastened together (e.g., by a tolerance fit, adhesive, and/or retaining members (e.g., set screws, C-clip, and/or other fasteners)). The shaft 1028 may have a threaded portion that extends away from the inner surface 1023 of the second side portion 1008. The threaded portion of the shaft 1028 may have external threads configured to engage the internal threads of the insert 1009 of the first side portion 1006 .

In some embodiments, the wheel 1026 can be sized such that it is slightly narrower in a lateral direction than a spacer 1030 connected to the inner surface 1023 of the second side portion 1008. This can allow the wheel 1026 to freely rotate relative to the first and second side portions 1006, 1008 when the knife 1000 is assembled and the first side portion 1006 is firmly pressed against the spacer 1030. The second groove 1011 in the first side portion 1006 can also facilitate rotation of the wheel 1026 relative to the first and second side portions 1006, 1008, for example, by providing space for a retaining member (e.g., a C-clip) for fixedly securing the wheel 1026 to the shaft 1028.

As best shown in FIG39 , the wheel 1026 can be sized and positioned so that at least a portion of the wheel 1026 extends outward from the handle portion and is exposed for use by the user. The wheel 1026 can be formed with circumferentially spaced ridges or teeth 1029 along its circumferential edge to enhance the user's grip. In use, the wheel 1026 can be easily rotated by manual pressure applied to the wheel by the user's digits (the user's finger or thumb) without the use of any tools. The wheel 1026 can be referred to as a "thumb wheel" because it can be easily rotated with the thumb.

To disassemble the knife 1000, the locking element 1014 can be moved from a closed or locked position to an open or unlocked position by rotating the actuator 1014b relative to the first side portion 1006 such that the actuator 1014b moves from one side of the first recess 1010 to the other. This rotates the hexagonal opening 1016 of the locking element 1014 relative to the hexagonal end portion 1022c of the rotating element 1022, aligning the hexagonal opening 1016 and the hexagonal end portion 1022c with each other and allowing the locking element 1014 to disengage from the end portion 1022c of the rotating element 1022. In this manner, the locking element 1014 and the hexagonal end portion 1022c can be moved laterally relative to each other, thereby loosening the grip or connection between the first and second side portions 1006, 1008 on the blade 1004. However, the first and second side portions 1006, 1008 cannot be fully separated from each other until the wheel 1026 is actuated to disconnect the first and second side portions 1006, 1008 at the opposite end of the handle portion. The wheel 1026 can be rotated in a first direction relative to the first and second side portions 1006, 1008. This rotates the shaft 1028 and retracts the shaft 1028 of the second side portion 1008 from the insert 1009 of the first side portion 1006. When the threads of the shaft 1028 disengage from the threads of the insert 1009, the first and second side portions 1006, 1008 and the blade 1004 can then be laterally separated from each other, as shown, for example, in Figures 37 and 40.

To assemble the knife 1000, the opening 1024 in the blade 1004 can be positioned over the rotating element 1022 of the second side portion 1008. The end portion 1022c of the rotating element 1022 can then be inserted through the hexagonal opening 1016 of the locking element 1014. The locking element 1014 can then be moved from an unlocked position to a locked position by rotating the actuator 1014b relative to the first side portion 1006, moving the actuator 1014b from one side of the first recess 1010 to the other. This causes the hexagonal opening 1016 of the locking element 1014 to rotate relative to the hexagonal end portion 1022c, causing the hexagonal opening 1016 and the hexagonal end portion 1022c to become misaligned, thereby causing the locking element 1014 to engage the end portion 1022c. In this position, the end portion 1022c engages the inner surface of the locking element 1014 and cannot be pulled through the opening 1016. As a result, the first and second side portions 1006, 1008 are prevented from moving laterally relative to each other, thereby holding the first and second side portions 1006, 1008 together and locking the blade 1004 between the first and second side portions 1006, 1008. The shaft 1028 of the second side portion 1008 can be inserted into the insert 1009 of the first side portion 1006. The wheel 1026 can then be rotated in a second direction (i.e., opposite the first direction) relative to the first and second side portions 1006, 1008, thereby pulling the first and second side portions 1006, 1008 laterally toward each other until the first and second side portions 1006, 1008 are securely held together.

In certain embodiments, the knife 1000 can further include a cap 1017, as best shown in FIG38 . The cap 1017 can be coupled to the first side portion 1006 and can be configured to couple the locking element 1014 to the first side portion 1006, as described further below. The cap 1017 can also be configured to cover the end portion 1022 c of the rotational element 1022, the first end portion 1014 a of the locking element 1014, and the hexagonal opening 1016 of the locking element 1014 to prevent debris from entering the hexagonal opening 1016 and/or accumulating on the rotational element 1022, which could potentially damage the knife 1000 or prevent convenient use, assembly, and/or disassembly of the knife 1000.

41 , in the illustrated embodiment, the cap 1017 includes an annular shoulder 1027, a first recessed portion 1018 disposed radially inward from the shoulder 1027, and a second recessed portion 1019 disposed radially inward from the first recessed portion 1018. The second recessed portion 1019 can have a depth greater than that of the first recessed portion 1018.

When the knife 1000 is fully assembled (e.g., FIG. 41 ), the first portion 1014a of the locking element 1014 is disposed within the first recessed portion 1018 of the cap 1017, and the shoulder 1027 of the cap 1017 surrounds the first portion 1014a except where the shoulder 1027 includes a groove 1031 through which the actuator 1014b extends. The groove 1031 is sized and shaped to allow the actuator 1014b to rotate or pivot relative to the first recess 1010 of the first side portion 1006.

Still referring to FIG. 41 , the second recessed portion 1019 of the cap 1017 can be configured to accommodate the end portion 1022c of the rotational element 1022. In certain embodiments, the second recessed portion 1019 can be configured such that a gap 1032 exists between the second recessed portion 1019 of the cap 1017 and the end portion 1022c. In some embodiments, the gap 1032 is approximately 0.1 mm to approximately 1 mm or approximately 0.2 mm to approximately 0.5 mm. In other embodiments, the gap 1032 can have any other dimensions to accommodate the end portion 1022c. The gap 1032 ensures that the end portion 1022c can extend completely through the hexagonal opening 1016 of the locking element 1014 without contacting the cap 1017. In the fully assembled state, the middle portion 1022b of the rotational element 1022 is disposed within the opening 1016 of the first portion 1014a of the locking element 1014. The width of the opening 1016 is greater than the diameter of the middle portion 1022b. This, in turn, allows the locking element 1014 to be easily actuated between the locked position and the released position. Thus, the gap 1032 can make assembly and disassembly of the knife 1000 easier than when the gap is not present. The gap 1032 can also accommodate variations in manufacturing tolerances (e.g., manufacturing tolerances of the handle portion 1002 and/or the locking element 1014).

As further shown in FIG. 41 , the inner diameter of the second recessed portion 1019 is larger than the outer diameter of the end portion 1022 c, defining an annular gap 1044 separating the end portion 1022 c from the surrounding wall of the recessed portion 1019. In some embodiments, the gap 1044 is between about 0.1 mm and about 1 mm, or between about 0.2 mm and about 0.5 mm, although in other embodiments the gap can be greater than 1 mm or less than 0.1 mm. The presence of the gap 1044 further enhances the ability to assemble and disassemble the blade 1000. The gap 1044 also further accommodates variations in manufacturing tolerances.

The cap 1017 can be connected to the first side portion 1006 via fasteners (e.g., screws), adhesives, and/or any other method for connection. For example, in some embodiments, the shoulder 1027 can include a threaded opening (not shown) configured to receive a fastener 1035, as shown in Figure 40. The fastener 1035 can extend through the first side portion 1006 and into a corresponding threaded opening in the shoulder 1027, thereby connecting the cap 1017, and therefore the locking element 1014, to the first side portion 1006.

As further shown in Figures 40 and 41, a shim 1040 can be positioned between the blade tang and the inner surface 1013 of the first side portion 1006 of the handle portion. In some embodiments, the shim 1040 can have a cylindrical portion 1040a and a flange portion 1040b. The cylindrical portion 1040a can be positioned within the opening 1007, while the flange portion 1040b can abut against the inner surface 1013 and contact the blade tang to reduce resistance to the blade tang during rotational movement of the blade. The cylindrical portion 1040a is desirably press-fitted within the opening 1007 so that the shim 1040 does not fall out under its own weight or separate from the first side portion 1006 during removal of the handle portion. If desired, the shim 1040 can be manually removed from the opening 1007 using fingers.

As further shown in FIG40 , another gasket 1042 can be disposed around the base 1022a of the rotation pin adjacent to the inner surface 1023 of the second side portion 1008. Similar to gasket 1040, gasket 1042 can have a cylindrical portion 1042a that is press-fitted into the opening of side portion 1008 and a flange portion 1042b that is positioned against the inner surface 1023. Gaskets 1040, 1042 can be made of a relatively low-friction polymer material (e.g., PTFE or nylon). In other embodiments, gaskets 1040, 1042 can be replaced with O-rings disposed in or positioned against the inner surface of side portions 1006, 1008.

Although not shown, another gasket (not shown) can be positioned within the recessed portion 1010 of the first side portion 1006 at a position between the first portion 1014a of the locking element and the adjacent surfaces of the recessed portion 1010 to reduce sliding friction between the locking element 1014 and the adjacent surfaces of the recessed portion 1010.

41, in some embodiments, actuator 1014b of locking element 1014 can include a hole 1033 and a spring 1034 and a ball 1038 disposed within hole 1033. Ball 1038 can be spherical and can have a diameter slightly smaller than the diameter of hole 1033.

As described above, the first recess 1010 in the first side portion 1006 can include a retaining opening or recess 1036. The retaining opening 1036 can have a diameter that is smaller than the diameter of the ball 1038. The retaining opening 1036 can be arranged in the first recess 1010 at a position corresponding to the locked and released configurations of the locking element 1014.

Thus, when the actuator 1014b is positioned so that the locking element 1014 is in the locked configuration or the released configuration, the ball 1038 is disposed over one of the retaining openings 1036, and the spring 1034 forces the ball 1038 partially into the retaining opening 1036. Thus, the ball 1038 and the retaining opening 1036 act as a stopper configured to selectively retain the actuator 1014b in the locked configuration and the released configuration. For example, this can help ensure that the actuator 1014b, and therefore the locking element 1014, does not inadvertently move from the locked position to the released position, or vice versa, without the user's intention to do so.

When the ball 1038 is disposed in one of the retaining openings 1036, the actuator 1014b can be moved by applying sufficient force to the actuator 1014b so that the first recess 1010 presses against the ball 1038 and the spring 1034 is compressed. This causes the ball 1038 to retract from the retaining opening 1036, thereby allowing the actuator 1014b to rotate relative to the first recess 1010.

In any of the embodiments described herein, any of a variety of mechanisms can be used to lock the blade of the folding knife in the open and closed positions, and a thumb stud can be used to prevent the blade from rotating when the blade is received in the handle portion. In addition, in any of the embodiments described herein, the knife can include one or more dowels or thumb-activated screws 984 (Figure 31), each dowel or screw extending through one side portion 906 and tightening into a threaded opening in the other side portion 908. The screws 984 allow the user to tighten the first and second side portions of the handle portion laterally to each other using manual pressure without the use of tools. In addition, in any of the embodiments described herein, a bearing system such as that described in U.S. Patent Application Publication No. 2012/0234142 can be included in the knife to reduce the friction applied to the blade of the knife, for example, when the blade is opened or when the blade is closed. In any of the embodiments described herein, the knife can be provided in a complete tool set with multiple blades or other tools. Because the folding knives described herein are easier to disassemble and reassemble than other known knives, any blade in the complete tool set can be easily installed in the knife according to the specific function desired. In any of the embodiments described herein, the knife may be provided with a clip secured to the handle portion so that the knife may be clipped to, for example, a user's belt or pocket.

Furthermore, unless structurally impossible, any feature described herein can be used in combination with any other feature described herein. For example, a folding knife can include a first side portion having an integrally formed locking element, such as in knife 200, and a second side portion having a recess and cavity for receiving the locking element, such as in knife 300. Similarly, a folding knife can include a first side portion and a structurally distinct locking element, which together can form an assembly, such as in knife 300, and a second side portion having an opening extending therethrough, such as in knife 200. In another embodiment, a folding knife can include the locking portion 840 of the embodiment of Figures 24-28 for securing the rear ends of the handle side portions together, and the locking element 926 of the embodiment of Figures 29-35 for securing the front ends of the handle side portions together.

The embodiments disclosed herein offer advantages over prior art folding knives, including prior art folding knives with detachable blades. For example, some knives disclosed herein have a simple construction, which can increase the knife's reliability and simplify the process of removing or replacing the blade. In the illustrated embodiments, the handle portion can be removed and the blade removed or replaced manually without the use of any tools, preferably without the need to remove small parts, thereby reducing or eliminating the possibility of losing parts of the knife.

For descriptive purposes, some aspects, advantages, and novel features of embodiments of the present invention are described herein. The disclosed methods, apparatus, and systems should in no way be construed as limiting. Rather, the present invention is directed to all novel and non-obvious features and aspects of the various disclosed embodiments, individually, in various combinations, or in sub-combinations with one another. The methods, apparatus, and systems are not limited to specific aspects or features or combinations thereof, nor are the disclosed embodiments required to have one or more specific advantages or solve problems.

Although the operations in some of the disclosed methods are described in a specific ordered order for ease of explanation, it should be understood that this description includes rearrangement unless a specific order is explicitly required. For example, the operations described in order can be rearranged or performed simultaneously in some embodiments. In addition, for the sake of simplicity, the accompanying drawings cannot show the various ways in which the disclosed methods can be used in combination with other methods. As used herein, the terms "one", "an" and "at least one" include one or more specified elements. That is, if there are two specific elements, there is also one of these elements and therefore there is "one" element. The terms "multiple" and "plurality" represent two or more specified elements.

As used herein, the term "and/or" used between the last two elements in a series means any one or more of the listed elements. For example, the phrase "A, B and/or C" means "A," "B," "C," "A and B," "A and C," "B and C," or "A, B, and C."

As used herein, the term "connected" generally refers to a physical connection or link and does not exclude the presence of intervening elements between the connected items unless otherwise indicated.

In view of the fact that the principles of the present invention can be applied to many possible embodiments, it should be understood that the embodiments shown are only preferred examples and should not be considered as limiting the scope of the invention. Instead, the scope of the claimed subject matter is defined by the following claims and their equivalents.

Claims (19)

1. A folding knife, comprising: A handle portion includes a first side portion and a second side portion laterally spaced from the first side portion, wherein the first side portion has a first opening and an outer surface of the first side portion has a groove surrounding the first opening; A rotating element extends from an inner surface of the second side portion; A blade is disposed between a first side portion and a second side portion, wherein the blade has a second opening in a shank portion of the blade, wherein a rotating element extends through the second opening, such that the blade is capable of rotating about the rotating element relative to the shank portion between an open position and a closed position; A locking element is at least partially disposed within the groove of the first side portion, wherein the locking element includes an actuator configured to move the locking element between a locked position and an unlocked position, wherein when the locking element is in the locked position, the locking element prevents disassembly of the first side portion and the second side portion, and when the locking element is in the unlocked position, the locking element allows disassembly of the first side portion and the second side portion. A cap, adjacent to the locking element, is connected to the first side portion and covers the first opening, wherein one end portion of the rotating element is sized to extend through the first opening into the cap, wherein the cap includes a groove through which an actuator of the locking element extends, and wherein the actuator is exposed from the cap and is rotatable relative to the cap; and A rotatable wheel is mounted on an axle between a first side portion and a second side portion of the handle portion. The axle has a first end portion and a second end portion. The first end portion of the axle is rotatably mounted to one of the first side portion and the second side portion of the handle portion. The other of the first side portion and the second side portion has a threaded opening that receives the second end portion of the axle. The wheel is rotatable to move the second end portion into and out of the threaded opening. The second end portion has an external thread that engages the internal thread of the threaded opening to hold the first side portion and the second side portion of the handle portion together when the second end portion of the axle is tightened into the threaded opening. 2. The folding knife of claim 1, wherein the actuator is movable relative to the groove of the first side portion between a first position and a second position, and wherein the locking element is in the locked position when the actuator is in the first position, and the locking element is in the unlocked position when the actuator is in the second position. 3. The folding knife of claim 1, wherein the end portion of the rotating element has a non-circular cross-sectional shape, wherein the locking element includes a first end portion, an actuator extending from the first end portion, and a non-circular opening formed in the first end portion, wherein the actuator is movable between a first position and a second position within the groove of the first side portion, wherein the movement of the actuator causes the non-circular opening to rotate relative to the rotating element, such that when the actuator is in the first position, the first end portion of the locking element engages the end portion of the rotating element, and when the actuator is in the second position, the first end portion of the locking element disengages from the end portion of the rotating element. 4. The folding knife of claim 3, wherein the end portion of the rotating element has a hexagonal shape and the non-circular opening has a hexagonal shape, wherein when the actuator is in the second position, the hexagonal shape of the end portion of the rotating element and the hexagonal shape of the non-circular opening are rotate aligned, and wherein when the actuator is in the first position, the hexagonal shape of the end portion of the rotating element and the hexagonal shape of the non-circular opening are rotate offset. 5. The folding knife according to claim 3 further includes: An aperture is formed in the actuator; A spring is arranged inside the hole; and A ball is at least partially disposed within the hole, and an outer surface of the recess has a retaining opening at a position corresponding to the first position and the second position of the actuator, such that when the actuator is in the first position or the second position, the ball is disposed on one of the retaining openings, and the spring forces the ball partially into the retaining opening to selectively retain the actuator in the first position or the second position. 6. The folding knife of claim 3, wherein the cap includes an annular shoulder, a first recessed portion arranged radially inward from the annular shoulder and having a first depth, and a second recessed portion arranged radially inward from the first recessed portion and having a second depth, wherein the second depth of the second recessed portion is greater than the first depth of the first recessed portion, wherein the locking element is at least partially arranged in the first recessed portion, wherein the annular shoulder surrounds the first end portion except where the annular shoulder includes a groove through which the actuator extends. 7. The folding knife of claim 6, wherein the inner diameter of the second recessed portion is greater than the outer diameter of the end portion of the rotating element, such that there is an annular gap that separates the end portion of the rotating element from the surrounding wall of the second recessed portion. 8. The folding knife of claim 6, wherein the annular shoulder includes a threaded opening, and wherein the folding knife further includes a fastener extending through the first side portion and into the threaded opening to attach the cap to the first side portion. 9. The folding knife of claim 6 further includes a washer disposed between the shank portion of the blade and the inner surface of the first side portion, wherein the washer has a cylindrical portion disposed in the first opening and a flange portion that contacts the shank portion of the blade. 10. A folding knife, comprising: A handle portion includes a first side portion and a second side portion laterally spaced from the first side portion, wherein the second side portion has a threaded opening; A shaft extends from the inner surface of the first side portion, wherein the shaft is rotatable relative to the first side portion and the second side portion, and wherein the shaft has an external thread portion capable of engaging the internal thread of the threaded opening. A rotatable wheel is disposed between the first side portion and the second side portion and connected to the shaft, such that the wheel and the shaft rotate together, wherein rotation of the wheel relative to the first side portion in a first direction causes the external threaded portion of the shaft to rotate in the first direction and extend into the threaded opening of the second side portion and engage the internal thread, thereby holding the first side portion and the second side portion together, and wherein rotation of the wheel in a second direction opposite to the first direction causes the external threaded portion of the shaft to rotate in the second direction and disengage from the threaded opening, so that the shaft no longer holds the first side portion and the second side portion together; and A blade is disposed between the first side portion and the second side portion, wherein the blade is rotatably connected to the handle portion such that the blade is rotatable relative to the handle portion between an open position and a closed position. 11. The folding knife of claim 10, wherein a portion of the wheel extends outward from the handle portion such that the wheel can be rotated by a user. 12. The folding knife of claim 10, wherein an annular outer surface of the wheel includes circumferentially spaced ridges. 13. The folding knife of claim 10, further comprising a rotating element extending from an inner surface of the first side portion, wherein the blade is disposed between the first side portion and the second side portion, and wherein the blade has a first opening in a foot portion of the blade such that the blade is rotatable relative to the handle portion about the rotating element between the open position and the closed position. 14. The folding knife of claim 13, wherein the second side portion has a second opening, wherein an outer surface of the second side portion has a groove surrounding the second opening, and wherein the folding knife further comprises a locking element disposed at least partially within the groove of the second side portion, wherein the locking element is movable between a locked position and an unlocked position, wherein when the locking element is in the locked position, the locking element prevents disassembly of the first side portion and the second side portion, and when the locking element is in the unlocked position, the locking element allows disassembly of the first side portion and the second side portion. 15. The folding knife of claim 14, further comprising a cap adjacent to the locking element, connected to the second side portion and covering the second opening, wherein one end portion of the rotating element is sized to extend through the second opening into the cap. 16. The folding knife of claim 15, wherein the locking element comprises an actuator movable between a first position and a second position relative to the groove of the cap and the second side portion, and wherein the locking element is in the locked position when the actuator is in the first position, and in the unlocked position when the actuator is in the second position. 17. The folding knife of claim 15, wherein the end portion of the rotating element has a non-circular cross-sectional shape, wherein the locking element includes a first end portion, a second portion having an actuator extending from the first end portion, and a non-circular opening formed in the first end portion, wherein the actuator is movable between a first position and a second position within the groove of the second side portion, and wherein the movement of the actuator causes the non-circular opening to rotate relative to the rotating element, such that when the actuator is in the first position, the first end portion of the locking element engages the end portion of the rotating element, and when the actuator is in the second position, the first end portion of the locking element disengages from the end portion of the rotating element. 18. The folding knife of claim 17, wherein the end portion of the rotating element has a hexagonal shape and the non-circular opening has a hexagonal shape, wherein when the actuator is in the second position, the hexagonal shape of the end portion of the rotating element and the hexagonal shape of the non-circular opening are rotate aligned, and wherein when the actuator is in the first position, the hexagonal shape of the end portion of the rotating element and the hexagonal shape of the non-circular opening are rotate offset. 19. A folding knife, comprising: A handle portion includes a first side portion and a second side portion laterally spaced from the first side portion, wherein the first side portion has a first opening and an outer surface of the first side portion has a groove surrounding the first opening, and wherein the second side portion has a threaded opening; A rotating element extends from an inner surface of the second side portion; A blade is disposed between a first side portion and a second side portion, wherein the blade has a second opening in a shank portion of the blade, wherein a rotating element extends through the second opening, such that the blade is capable of rotating about the rotating element relative to the shank portion between an open position and a closed position; A locking element is at least partially disposed within the groove of the first side portion, wherein the locking element is movable between a locked position and an unlocked position, wherein when the locking element is in the locked position, the locking element prevents disassembly of the first side portion and the second side portion, and when the locking element is in the unlocked position, the locking element allows disassembly of the first side portion and the second side portion; A cap, adjacent to the locking element, is connected to the first side portion and covers the first opening, wherein the cap has an inner portion and an outer portion, wherein one end portion of the rotating element is sized to extend through the first opening into the inner portion of the cap, and wherein the cap includes a groove through which a portion of the locking element extends from the inner portion of the cap through the groove into the outer portion of the cap; and A rotatable wheel is disposed between the first side portion and the second side portion and connected to a shaft extending from an inner surface of the second side portion. The shaft has an external thread portion capable of engaging the internal thread of the threaded opening. Rotation of the wheel relative to the first side portion in a first direction causes the external thread portion of the shaft to extend into the threaded opening and engage the internal thread, thereby holding the first side portion and the second side portion together. Rotation of the wheel in a second direction opposite to the first direction disengages the external thread portion from the threaded opening, so that the shaft no longer holds the first side portion and the second side portion together.